Coinfection with HIV and Mycobacterium tuberculosis is associated with high rates of active tuberculosis and possibly an acceleration of the progression to clinical AIDS. Elucidating the interplay of the immunopathogenic events that occur as a result of HIV/M. tuberculosis coinfection is, therefore, of central importance for understanding the immune sequelae of this coinfection. We have shown that macaques coinfected with SIV and Mycobacterium bovis Bacille Calmette-Guerin (BCG) develop a syndrome similar to AIDS-related tuberculosis. Using this SIV/BCG coinfection model, we plan to study the immunopathogenesis of AIDS virus interactions with mycobacteria and the evolution of tuberculosis.